Figure 2 . (a) Descent rate of float WMO 3902151 at cycle 41,
located on the western flank of the Mid-Atlantic Ridge in the Brazil
Basin. Raw values from first differences of pressure over time (black
dots), values at 10 dbar intervals derived by filtering raw values with
a 150-dbar lengthscale Loess smoother (black curve), and background
values (red dashed line) estimated from a 2nd order
polynomial fit to the filtered values vs. pressure for 1000 dbar to the
bottom value. (b) Power spectrum for the Morlet wavelet transform of the
residual w’ (filtered minus background) vertical velocity from
panel (a) with contours at uniform intervals and the location of the
maximum of the power spectrum (large red dot), disregarding values in
the “cone of influence” affected by zero-padding of edge values (which
has been masked with white in the figure).